Skip to content

Rainfall data for SCIMAP?


How can I get hold of the rainfall grid that you refer to in the SCIMAP manual?


The data is freely available from the Met Office it is UKCP09 data but you can’t transfer the data from person to person, you have to apply for it. You can either:

1)      register to use the data. You register at:

A reasonable statement of purpose for SCIMAP would be:

“monthly average rainfall data will be aggregated to an annual average to use as a weighting factor within SCIMAP, a diffuse pollution risk profiling tool”

Once you have registered to use the data and that has been approved by the Met Office either you can generate the annual average rainfall intensity grid by taking the average of the monthly average rainfall intensity grids (“Total precipitation” in

2)      still run SCIMAP but assuming the average annual rainfall is spatially uniform over your catchment. Depending on where you are working this may or may not be a reasonable assumption. However, it will allow you to continue testing SCIMAP. To do this you need to take the following steps in SAGA:

a.       Ignore earlier mentions of the rainfall grid then just before you get to the step where you run SCIMAP you should go to the “Modules” tab then “Grid – Tools” then “create Constant Grid”.

b.      Choose the “Grid system” that has the DEM and landcover map that you want to use in SCIMAP

c.       Choose the DEM that you want to use in SCIMAP as your “>>Base Grid”

d.      Leave “Value” set to 1 & hit “Okay”

e.      A new grid will be generated with the same extent as the DEM but made up entirely of 1s.

f.        Now run SCIMAP but in the “>> Rainfall Pattern box” choose the new grid of 1s.